You can find Spline's camera controls on the bottom center of the Viewport.
By hovering the camera orientation icon you'll be presented with different options to choose from to quickly view your scene from the Top, Bottom, Left, Right, etc.
Below that there are two different camera views to choose from. Orthographic and Perspective.
- Orthographic: All angles are parallel.
- Perspective: All angles change based on the distance from the camera to the object
Here's also where you'll find the zoom options where you can quickly change between already predefined zoom values.